Direct reduction with coal gasification and coke oven gas

Abstract

A method and apparatus for producing direct reduced iron (DRI), including: generating a reducing gas in a coal gasifier using coal, oxygen, steam, and a first coke oven gas (COG) stream as inputs to the coal gasifier; and delivering the reducing gas to a shaft furnace and exposing iron ore agglomerates to the reducing gas to form metallic iron agglomerates. The method further includes delivering a second COG stream directly to the shaft furnace.

What is claimed is: 
     
       1. A method for producing direct reduced iron (DRI), comprising:
 generating a reducing gas in a coal gasifier using coal, oxygen, steam, and a first coke oven gas (COG) stream as inputs to the coal gasifier, wherein the first COG stream is reformed by the coal gasifier and tar and heavy hydrocarbons in the first COG stream are converted to one or more of a reducing gas component and an oxidant in the coal gasifier; and 
 delivering the reducing gas to a shaft furnace and exposing iron ore agglomerates to the reducing gas to form metallic iron agglomerates. 
 
     
     
       2. The method of  claim 1 , further comprising delivering a second COG stream to the shaft furnace. 
     
     
       3. The method of  claim 2 , further comprising delivering the second COG stream to one or more of a transition zone and a cooling zone below a primary reducing zone within the shaft furnace. 
     
     
       4. The method of  claim 1 , further comprising removing sulfur from the reducing gas prior to delivering the reducing gas to the shaft furnace. 
     
     
       5. The method of  claim 1 , further comprising heating the reducing gas prior to delivering the reducing gas to the shaft furnace. 
     
     
       6. The method of  claim 1 , further comprising compressing the first COG stream. 
     
     
       7. The method of  claim 2 , further comprising compressing the second COG stream. 
     
     
       8. The method of  claim 2 , further comprising removing one or more of tar and heavy hydrocarbons from the second COG stream. 
     
     
       9. The method of  claim 1 , wherein the first coke oven gas stream is input to the coal gasifier coincident with the oxygen. 
     
     
       10. The method of  claim 1 , wherein the first coke oven gas stream is input to the coal gasifier coincident with the coal. 
     
     
       11. The method of  claim 1 , further comprising recycling a top gas stream from the shaft furnace to the shaft furnace as part of the reducing gas after one or more of cooling the top gas stream, cleaning the top gas stream, compressing the top gas stream, and removing carbon dioxide from the top gas stream.